There are more than twenty-five million citizens in the United States who are temporarily or permanently totally disabled. These people reside in nursing homes, hospitals, rehabilitation facilities or in homes where they are totally dependent upon the care of others for their survival. Many of these people suffer from obesity and are unable to assist or only partially assist in their own care or handling. Many are confined to bed unless removed from their beds by attending persons. The typical method of removing a disabled person from a bed is to raise the disabled person to a sitting position, rotate the patient to a sitting position on the side of the bed and with an attendant under each arm and an attendant standing and facing the patient, stand or pick the patient up and then turn and lower the patient into a chair, wheelchair, geriatric chair, or on to some other conveying mechanism. The increase in such patients that are in excess of three hundred pounds in body weight has greatly exacerbated the foregoing methodology.
The result of physically handling disabled and obese persons is that many sustain spontaneous bone fractures, muscle and ligament pulls or tears, or pain solely from the physical handling and lifting. Another direct consequence of the existing practice outlined above is that the attendants suffer high incidents of injuries to their backs, muscles or ligaments as a result of physically lifting disabled, obese persons from sitting positions onto beds and returning them to their sitting positions. This consequence usually requires that institutions pay the highest workman's compensation insurance rates, and are required to hire additional attendants to perform the lifting and handling of disabled persons. In the home environment the consequence is that the disabled person is essentially confined to bed.
Thus, the problem is that millions of disabled obese persons in institutions or at home are being moved from beds to chairs or other appliances by the physical strength of their attendants with resulting injuries both to the patient and attendants; or the patient is never or seldom moved from the bed, with resulting bed sores, bad hygiene and circulatory problems. Such problems have greatly increased the cost of care of disabled persons through high insurance costs, additional labor, injuries and litigation.
Combined chair and gurney systems are well known in the art. For example, U.S. Pat. No. 2,587,068 shows a combined chair and gurney which is convertible from a chair to a gurney at the same height as a bed or operating table for transfer if desired. A frame supporting the patient is mounted for pivotal movement between various positions on a lower support frame mounted between wheels or casters. The seat supporting the patient remains in a horizontal position at all times and can not be inclined. Also, side frames are not provided alongside the seat at all times for support of the patient.
U.S. Pat. No. 3,147,039, shows a combined wheelchair and gurney which is convertible for transport of a patient either in a sitting or lying position. A pair of side frames are provided to support a linkage for converting the transportation of a patient between a sitting position and a lying position. The back seat frame and the leg seat frame are both connected to and supported by the opposed side frames, and the seat frame remains positioned horizontally at all times.
U.S. Pat. No. 4,717,169, discloses the concept of a wheeled structure that is readily convertible between a full-sized bed and a wheelchair. This is different from the teachings of the present invention in that the unit does not include any mechanism to facilitate a rearward shifting of the patient's center of gravity, or transferring the patient from the bed arrangement onto another like bed.
U.S. Pat. No. 4,787,104, discloses the concept of a convertible hospital bed that includes mechanism to assist moving a patient that is in the bed into a sitting position and off the bed. These teachings are only generally related to the present invention, and fail to include a wheelchair unit that is convertible into a gurney or the concept of a rearward shift of a patient's center of gravity.
U.S. Pat. No. 4,821,352, discloses an arrangement combining a wheelchair with a bed, wherein the bed has mechanism that assists in lifting an invalid from the bed into a wheelchair with the wheelchair having a mechanism to receive the invalid from the bed. The wheelchair unit is different from that of the present invention since it fails to include structures which include any mechanism to facilitate a rearward shift of the patient's center of gravity, or permit transfer of an invalid between a bed and a convertible wheelchair, where the convertible wheelchair is located adjacent the side of the bed.
Reclinable wheeled chairs are also known in the art, for example, U.S. Pat. Nos. 1,748,784; 2,587,068; 2,682,913; 2,694,437; 2,869,614; 2,913,738; 3,147,039; 3,284,093; 3,344,445; 3,406,772; 3,967,328; 4,190,913; 4,255,823; 4,285,541; 4,361,917; 4,381,571; 4,432,359; 4,453,732; 4,717,169; 4,726,082; 4,787,104; 4,839,933; 4,856,123; 4,858,260; 4,966,379; 4,997,200; 5,048,133; 5,971,482; 5,996,716; 6,003,891; and 6,158,810 disclose various wheeled chairs, many of which focus shifting the orientation of a patient from a seated position to a supine or prone position to aid in patient care. These prior art wheeled chairs provide transportation and mobility to patients, while allowing the patient to recline to a prone position for comfort. Although conventional wheeled chairs provide the above-mentioned features, conventional wheeled chairs have limited capabilities.
For example in many of the foregoing prior art devices the process of transitioning a patient from an upright, seated position to a supine, prone position relies upon a seat structure that relies upon a “parallelogram” linkage to effect the transition. Since the length relationship among the links always remains a constant during operation of such prior art “parallelogram” linkage-based seats, a shift in the center of mass of the patient outwardly very often results, giving the patient a sensation of sliding from the chair. This sensation is disconcerting to the obese patient, and thus often requires more than one caregiver, and great effort by the patient, to maintain the patient's sense of safety during transition from sitting to reclining or vice-a-versa.
What is needed in the art is a wheeled chair, which provides a simple, safe, and cost-effective way of transitioning a patient from an upright, seated position to a supine, prone position and vice versa. What is also needed is a wheeled chair and gurney combination, which simplifies the patient transfer process and enhances the safety of that process.